(2de) Developing a Sustainable Future through Research and Education in Synthetic Biology and Metabolic Engineering of Clostridia

According to Environmental Protection Agency (EPA), 1.4 billion metric tons of greenhouse gases were emitted during industrial production in the United States (2021), corresponding to 23% of total greenhouse gas emissions. Without establishing a bioeconomy capable of manufacturing commodity chemicals, materials, and fuels from renewable feedstocks, realizing the ultimate CO₂ neutral economy is likely difficult. My research goals include developing bioprocesses converting renewable feedstocks into various chemical products to help realize the circular bioeconomy for a sustainable future. My research has primarily focused on synthetic biology and metabolic engineering of industrially relevant Clostridia such as woody biomass fermenting Clostridium thermocellum, solvent producing C. acetobutylicum, and gas fermenting C. ljungdahlii.

The past 10 years of interactions with mentors, mentees, and students have constantly motivated me to contemplate the type of leadership that is required to engage individuals with diverse backgrounds, personalities, and knowledge for tackling high-impact problems. The joyful and inspiring challenges in both classroom and laboratory have led me to a deep passion for developing my independent research and teaching programs. In this poster, I will present plans and strategies for successfully launching and maintaining the programs.

Research Interests: Synthetic biology and metabolic engineering of Clostridia.

Microbes evolutionarily close to each other often exhibit metabolic modularity, which allows for the development of more effective engineering strategies to harness their metabolism for biochemical production, including alcohols, amino acids, and organic acids. An industrially attractive microbial class is Clostridia, which are obligate spore-forming anaerobic bacteria commonly found in a wide range of natural environments such as soil, sewage, marine sediments, animal intestine, and plants. Due to the wide range of habitat, many Clostridia have evolved to rapidly catabolize a variety of renewable materials including lignocellulosic biomass and CO₂ gas, beneficial for economically feasible bioprocess development. However, their conversion capabilities for a broad range of value-added biochemical and biofuel production have largely been underappreciated. My research interest is engineering Clostridia to understand the uniquely attractive characteristics and leverage their metabolic capabilities to tackle sustainability problems in chemical manufacturing.

My research has focused on unraveling metabolic modularity of Clostridia and developing design principles to rapidly rewire their metabolism. More specifically, I have aimed to effectively integrate synthetic biology, metabolic engineering, protein engineering, and systems biology for engineering metabolism of Clostridia at multiple scales. For example, my PhD dissertation demonstrated a modular design framework of ester biosynthesis at molecular, cellular, and community levels. The study interconnected protein engineering with whole-cell biocatalysts and developed a novel Acetivibrio thermocellus (also known as C. thermocellum) ester biosynthesis platform that directly converts lignocellulosic biomass into volatile short-chain esters at elevated temperatures. The Clostridium synthetic biology study extended to my postdoctoral research on engineering a syntrophic Clostridium consortium consisting of C. acetobutylicum and C. ljunghdahlii that enables mixotrophic biochemical production with CO₂ fixation.

As a future research program, I am interested in rational design of Clostridium relevant syntrophic microbial consortia for development of novel biocatalysts. While microbes in nature exist in a consortium where multiple species interact with each other, the past century of microbiology and bioengineering have mostly focused on individual strains. Advances in biotechnology enabled analyzing various microbial consortia such as gut microbiome at multiple scales, providing exceptional opportunities for modular design of novel biological systems. Recently, new types of cell-to-cell physicochemical interactions in Clostridia relevant microbial consortia have been discovered using state-of-the-art technologies. Especially, the cell-to-cell interactions facilitate direct cellular material exchanges, enabling more carbon and energy efficient fermentation. Since Clostridia reside in a broad range of environments where various microorganisms co-exist, understanding and harnessing the interspecies communication within Clostridium relevant consortia will provide important fundamentals for effective design of industrially valuable microbial consortia. Such advancement will pave the way for the development of next-generation bioprocesses that can overcome limitations of conventional fermentation technologies such as unsatisfactory economic feasibility and compromised theoretical maximum yield caused by carbon loss via CO₂ release.

Teaching interests: Bioprocess engineering, biomolecular engineering, microbiology, and biochemistry.

I define teaching as a process of guiding because learning is an inherently individual process. When I served as a teaching assistant for the reactor fundamental class with an average number of 90 enrolled students, I had opportunities to witness that each person has their own way of efficiently digesting information and assimilating knowledge. To help students develop their own learning processes, I will design classes that encourage self-directed learning. According to Association for Psychological Science (APS) (H. Pashler et al., Organizing instruction and study to improve student learning, 2007, NCER 2007-2004), asking deep explanatory questions is recommended as a key principle to improve student learning. My pursuing teaching style matches with the recommendation, helping students build explanations by asking deep questions.

My teaching interests are fundamentals of bioprocess engineering, biomolecular engineering, microbiology, and biochemistry relevant to biotechnology applications. During mentoring 20 students in labs, I have observed how the different disciplines including chemical engineering, bioscience, agricultural engineering, biological engineering, microbiology, and biomedical engineering can be synergistically combined into bioengineering and biotechnology. To maximize the ‘melting pot’ value of my research topics, I aim to develop classes that foster practical mindsets grounded by fundamentals through practice of defining real-world problems and identifying possible solutions based on knowledge.

Overall, I aspire to be a teacher who guides students to practical problems by asking questions. In the era of artificial intelligence, the pursuit of ‘correct answers’ has diminished in value compared to the appreciation of ‘unique answers.’ Therefore, the academic standards will be determined by observing students’ thinking process, rather than judging whether their answers are correct or wrong.

Statement of contribution to diversity, equity, and inclusion: Jeong.

Korean culture is often defined as ‘Jeong.’ It is a cultural value described as a feeling of loyalty and strong emotional connection between people. The core of ‘Jeong’ is empathy, which distinguishes it from kindness. It involves genuinely caring for students, not only their education, but also overall well-being, recognizing various aspects of their lives that can impact their educational journey. The vision of my contribution to diversity in research, teaching and service is based on ‘Jeong.’ College education is not fully accessible to everyone due to not only financial reasons, but also cultural and personal reasons, and every community possesses unique circumstances that could cause diversity and equity issues. Regardless of the different circumstances, ‘Jeong’ will remain a key value that guides my commitment to fostering diversity within the communities I belong to. Experiencing is one of the most effective ways to learn and appreciate the value of diversity, equity, and inclusion in the workplace. Therefore, my goal is to foster a positive and inclusive climate in the workplace, where students, mentees, and colleagues can consistently engage in collaborative work and experience the benefits of working together. With the concerted efforts, I believe the climate of inclusion, belonging, and respect will be maintained and spread out to larger communities.